Seagate ST3146954FC User Manual
26
Cheetah 15K.4 FC Product Manual, Rev. B
[1] Measured with average reading DC ammeter. Instantaneous +12V current peaks will exceed these val-
ues. Power supply at nominal voltage. N (number of drives tested) = 6, 35 Degrees C ambient.
[2] For +12 V, a –10% tolerance is allowed during initial spindle start but must return to ±5% before reaching
14,904 RPM. The ±5% must be maintained after the drive signifies that its power-up sequence has been
completed and that the drive is able to accept selection by the host initiator.
completed and that the drive is able to accept selection by the host initiator.
[3] See +12V current profile in Figure 2.
[4] This condition occurs when the Motor Start option is enabled and the drive has not yet received a Start
[4] This condition occurs when the Motor Start option is enabled and the drive has not yet received a Start
Motor command.
[5] See paragraph 6.2.1, "Conducted noise immunity." Specified voltage tolerance includes ripple, noise, and
transient response.
[6] Operating condition is defined as random 8 block reads at 225 I/Os per second for ST3146954FC models
Table 3:
DC power requirements for ST373554FC drives
Notes
1 Gbit mode
2 Gbit mode
4 Gbit mode
(Amps)
(Amps)
(Amps)
(Amps)
(Amps)
(Amps)
Voltage
+5V
+12V [2]
+5V
+12V [2]
+5V
+12V [2]
Regulation
[5]
±5%
±5% [2]
±5%
±5% [2]
±5%
±5% [2]
Avg idle current DCX
0.62
0.57
0.66
0.56
0.69
0.57
Maximum starting current
(peak DC) DC
3
σ [3]
0.83
1.88
0.94
1.85
0.77
1.71
(peak AC) AC
3
σ [3]
0.98
4.08
1.11
4.08
1.17
2.94
Delayed motor start (max) DC 3
σ [1] [4]
0.54
0.03
0.58
0.04
0.70
0.04
Peak operating current:
Typical DCX
0.79
1.01
0.90
0.66
0.76
0.79
Maximum DC
3
σ [1]
0.82
1.03
1.18
0.67
0.77
0.80
Maximum (peak) DC
3
σ
1.27
2.82
1.24
2.98
1.30
2.82
Table 4:
DC power requirements for ST336854FC drives
Notes
1 Gbit mode
2 Gbit mode
4 Gbit mode
(Amps)
(Amps)
(Amps)
(Amps)
(Amps)
(Amps)
Voltage
+5V
+12V [2]
+5V
+12V [2]
+5V
+12V [2]
Regulation
[5]
±5%
±5% [2]
±5%
±5% [2]
±5%
±5% [2]
Avg idle current DCX
0.62
0.43
0.66
0.43
0.69
0.43
Maximum starting current
(peak DC) DC
3
σ [3]
0.83
1.59
0.93
1.58
0.98
1.59
(peak AC) AC
3
σ [3]
0.99
3.43
1.11
3.30
1.16
3.36
Delayed motor start (max) DC 3
σ [1] [4]
0.55
0.03
0.58
0.03
0.62
0.03
Peak operating current:
Typical DCX
0.77
0.87
0.81
0.86
0.84
0.87
Maximum DC
3
σ [1]
0.81
0.89
0.85
0.88
0.88
0.88
Maximum (peak) DC
3
σ
1.26
2.64
1.31
2.54
1.35
2.59